Tank purging apparatus



Aug. 27,1946. H. E. HElGls '2,406,373

TANK PURGING APPARATUS Filed sept. 19, 1942 2 sheets-sheet ,2

INVENTOR ATTORN Patented Aug. 27,' 1946 Y UNITED STATES PATENT j-FI-CE h '2,406,3rj

l TANK PURGING Arraiwrus .fneilrynrnst Heig'is, Nutiey, N. 1.,.assignerto4 ffSzpecialties Development, Corporation, Bloom.-V

` field, N. .La corporation ofNewJeI-sey y Application september 19, 1,942, serial No. 459,022 y 1 The present-invention relates to fuel .tank .purging and vapor diluting apparatus, and to a adapted tebe 4.used in :connection with such apparatus. I

. VV'Etre-.fueltanks vof military aircraft usually are provided with onehor more )venting 'passages or openings which permit therapid escape cf-fuel vapors vformed vin the tanks, wh'erebyexplosive vaporY .mixtures Vare minimized or eliminated,

which .are likely -to explode the. event the ltanks are pierced `by guniire orlthe like. These ventingpassages normailylare open, but may be closed by -a valve-inemberresponsive vto :inert-a or nthe nsurge of .theiuel `in 4the tank when .plane is .eatapuited .into-night or is .brought to asudden stop While landing, whereby thespillage'oi fuel through venting passages is prevented.

It .is customary to-further minimize or eliminate the presence of explosive vapor 1mixtures Vin the fuel tanks while the plane is ina combat area by introducing an inert, non-combustible gas, such as carbon dioxide, which purges the vapor space or dilutes the vapor suiciently to render them non-explosive. Where lsuch. a purg-Y ing or vapor diluting medium is introduced into tanks having an inertia, or surge operated fvalve, it has been found that the pressure of the medium operates the valve to cloee the-venting passages. The closing of the valve Acauses the rnedium to build up a pressure in the' tanks which may eventually burst the tanks, and valso'prevents the vapor mixtures from being Yremoved from the tanks.

An object of the present invention 'is to provide a, fuel tank purging and vapor diluting apparatus which overcomes the foregoing dilliculties.

Another object is to provide an improved apparatus, wherein an inert medium 'under pressure is introduced into the vapor space of a fuel tank and the pressure of the medium is utilized for maintaining the vent passage valveA in open position.

Another object is to provide an apparatus of the foregoing character which assures proper purging or vapor dilution While the plane is in Y eight.

Another object is to provide a simple.. com pact, inexpensive fitting comprising a. vent, an inertia or rsur-ge operated valve -for closing the vent, means for introducing an inert medium, and means for preventing the valve from closing 'while the medium is Vbeing introduced.

Another object is to provide a tting of the foregoing character, wherein leakage of the fuel 21 claims. (Otago-[sci into `thefpurginglor. .vapor diluting vmedium delivi ery conduit :is prevented. 1

qAnother.object to provide a iitting of the foregoing character which is automatic in opereration yand requiresrfa `minimum amount of vinspection andrepair..`

Another object Visto provide -a fittingof the foregoing. character Whichfis readily7 assembled installed. 1 v 'l l A f f A-further object consistsinthe construction, arrangement and operation of parts, Wherebyzthe Y foregoingtobjects are attained. v

l Other and `further objects of the invention will be obviousupon :an understanding .of the-illus- VAtrativeembodiment 4about nto be described., for Will be .indicated .in `the appended claims, and various advantages not referred to herein will occur to .oneskilled in the-.art uponempleyment of Athe invention inpractice..- .A preferred. embodiment of the inventionhas beenchosen for A.purposes-fof lillustration and: description andois shown lin .the accompanying drawings, forming a part of the specification, v,vvhereinin f Figure l is; aidiagranimatiel view `-oi an airplane having fuel tank purging or .vapor diluting apparatua illustrating .aner'nbodiment of the invention.:

Figure .2 .is li-zed in connectionwith-theapparatus shovvn'fin Figure 4l. f v. Figure .isa bottom plan View off'the tting..

Figure 4 is ka sectional view taken along the yline 11-4 ori-Figure 2.. v

Figure 5 is a partial sectional `View taken sub `stantiallv along the yline 5 5 on Figure 2.

Referring to the drawings, and more particularly to Figure 1. there is shown an airplane having a kfuel tank l in its fuselage. Adjacent each end of the tank., a tting AIl is Vattached to the top wall of the tank.. The rttngs have an opening adapted to vent the vapor `space of the tank to `the atmosphere .by Way of a conduit, and have means for introducing an inert purging and vapor diluting medium, such `as gaseous car-bon dioxide under pressure. The fittings -are each provided with. valve member l2. suchas a Happer, for closingla ventopeninginthe ttings in response to inertia orV surges ofthe fuel. The fitting at Fthe forward end of the tank is arranged so that the valve member or flapper I2 closes the vent .opening upon a forward surge of the fuel which may occur when the plane is brought to an Y abrupt stop whilelanding; and the tting at `*the rearward end of the tankis arranged sovthat its an elevation-.al View of a giitting .u-ti-l flapper closes the Vent opening upon a rearward be a cylinder I4 containing carbon dioxide, which is suitably located in the fuselage. The cylinder I4 is provided with Ya discharge control heard `I5 Y of suitable design adapted to 'be operated in any desired manner, for example, by ai pull cable: I6 having a handle I1 attached thereto and mounted 'Y on the instrument panel. V

Ril

erally described, the body 25 houses a piston operated plunger 65 adapted to extend outwardlyV from the body and engage the extension 32 of the flapper to prevent it from closing the venting passage. The conduit 2 I is suitably connected to the body 25 and supplies the purging or vapor diluting medium under pressure which is adapted to operate the plunger. body for conducting the medium operating the plunger to an orifice 33A which meters the medium into the tank. Preferably the Vorifice 33 is formed in a sleeve38, closed at one end and removably During purging or vapor dilution, .it is desired that the pressure in the fuel tank does not exceed two pounds perV square. inch above the atmos-` 'pheric pressure to which the tank is subjected.

Since the pressure V'of the carbon dioxide in the Y cylinder I4 w may vary between 145' and 3000 pounds per square inch, depending upon `atmospheric conditions, suitable pressure regulating Yand reducing meansy are provided. y Preferably,

` these means comprise a pair of pressure regulators I9 and 20 connected in series in a conduit 2| leading from the'cylinder I4 to the fittingsv I'I.

The rst regulator I9 may be adjusted to reduce the-'pressureat its outlet to atleast 200 pounds,v

secured to the body by aV threaded connection.

Y v,In order to accomplish the foregoing, the body has an upper portion'35 which extends above the flange 22, and has a lower portion adjacent theventing body 24 which is adapted to extend into the tank. The lower body portion is provided with a chamber 31, which is enlarged at its upper end, and which terminates in an opening vat its lower end. "Adjacent the opening,

an annular shelf 4I is provided in the chamber for supporting Ya flanged bushin`g`42 extending per squareV inch, while lthe second regulator 20 y VVmay be adiusted to reduce the pressure Vat 'its outlet tor about ,115`V poundsper square inch. As

will be described hereinafter, the ttingsiII are provided with a metering orifice adapted to re-l` duce the pressure to labout two pounds per square inch. Y

By providing a primary and secondary'regulator for regulating the pressure in two stages,

more accurate regulation is attained. Suiiicient vcarbon dioxide is supplied at all times without danger ofV bursting the tank due to excessive pressures InFigures 2. 3, 4 and 5, the Lfitting II'Y is illus# ,'trated in detail. The fitting comprises a'ange `22adaptedto be securedto the wall ofthetank, and a venting body 24 kand body 25 housing the flapper operating means carried by the ange (Figure 2). The ventingbodyis substantially tubular and has a venting passage or openingv 2B extending therethrough (FigureA). portionpf the Vventing body extends above the flange 22 and is in the form of a threaded sleeve 21 adaptedfoi` connecting the venting conduit 9 thereto. 'I'helower portion of the venting body is adapted to extend into the tank andthe lower 'end thereof is provided with ran, annular lip 29, inclined slightly with respect to the horizontal, against which the apper or valve memberV I2 is adapted to abut to close the venting passage 26.

The upper As shown in Figures 2 and 4, the flapper I'2 is pivotally supported by a rod or pin 30 carried byV `the., ilap'pe'r operatingmeans about to bedelscribed.` The flapper I2 may be provided with a Vcounterbalancing larm 34 Aadapted to facilitate' actuation of the flapper in response to inertia .or surgeof the fuel. Y h

Y LIn Figure 5, the body 25 housing the flapper operating means is Villustrated in detail., G611- through the opening. A second annular; shelf` 44 is located at the lower end of the enlarged upper portion of the chamber 31 and la ring-shaped gas- Y ket 45 is supported, which is retained on 4the shelf by a cylindrical sleeve 45 tted into the enlarged chamber portion. The sleeve 46 has an'aperture 41 adapted to conduct the-purging or vapor diluting medium to a passage-49 leading to the orifice 33 for delivering the medium to the tank. In

order'to maintain the sleveaperture 41 in alignment with the passage 49, a set screw 50 Vmay be threaded through the wall of the body to t into a notch 5| or recess formed in the sleeve, A

The the upper end of 'the' chamber, av ringshaped gasket 52 is seated on a shelf 54 and on the upper end of the sleeve v4e, and a iiange 55 of a disc-shaped member 5 5 is' in turn seated on the gasket 52. A gasket 51 is seatedv on the ange 55 and is engaged by the lower end of a chambered bushing member 59 threadedly secured in the upper portion 35 ofthe body 25. The upper end of the bushing member has a threaded connection for Asecuring the conduit 2 I. f When the bushing member 59 is threaded into position, pressure is ex erted on the gaskets 45, 52 and, 51 to form seals between .thelparts which 'the gaskets are interposed. Y l ,l

` The disc-'shaped member 55 has a central aperture 6D into which isV insertedgat its'upper end, a cylindrical strainer 6I housed in the 4chamber of the bushing member. This strainer prevents foreign matter such as dust orcorroded'metal particles from reaching the orifice 33 and causing it to become partly or completely clogged. At the lower end of the aperture 59, a downwardly facing annular valve seat 52' is provided against which a valve member, about to be described, is

Vadapted to abut;

VThe meansfor preventing the flapper i2' from closing the venting passage, comprise the plunger 55 located in thechamber 31 of the body 25, one end of which is adapted to extend downwardly and outwardlythrough the opening 4) and engage the extension 32 of the .flapperg and apis-V ton 6.6 attached to the other end ofthe plunger and slidably positioned in the sleeve 45. The piston is provided with an upwardly facing valve disc 51 adapted to abut the valve seat Bland with a downwardly facing annular seater sealing Y ridge 68 adapted to engage the gasket 45. The plunger is adapted to be normally maintained in the position'shown in Figure 5 by a Provision -islma'de in ther cylindrical helical spring 69 .telescoped about the plunger. The .spring is under compression 'and has one end engaging the underside of the piston and has itsother end seated on the flanged bushing 42, whereby the piston is urged upwardly to Icause the valvedisc 61 to close 'the opening 60. The piston and 'the aperture 4.1 inthe sleeve are -so related that 'the piston may be moved downwardly beyond the aperture 41, whereby .the medium 'under Lpressure .acting on the piston passes through the aperture 41 .and is conducted to the .orifice 133. When the piston is driven .downwardly, the .ridge 68 vengages the gasket -4'5 to prevent leakage of the medium through .the opening l0.

.inthe operation of the apparatus, the plunger .65 normally is in its .retracted position, as shown in Figure 5, and the iiapper is spaced .slightly away from the lip 29 .of the fventin'g passage 26, as shown in Figures 2 and 4. In the event the plane is catapult-ed into night, a surge of fuel toward .the .fitting .fl I will cause the flapper to close the venting passage. During normal flight the flapperzremains spaced away 'from .the passage to .allow fuel vapors to pass to the atmosphere by way of the conduit 9.

While the plungei-.is retracted, dueto the spring 69 urging the piston upwardly, the valve Idisc V61 closes the `opening .6.0, whereby the plunger and its :associated parts fact las a check lvalve 'for Apreventing ;fuel from .getting into .the purging medium conduit 2|.

When the pilot venters :a combat area or .anticipates `.being attacked, he operates the vapor diluting `or purging apparatus by pulling the handle l1 .attached tothe .pull :cord -Hi which .in turn :operates .to control head |:5 to :effect discharge of the carbon dioxide or other medium in the cylinder 14. The pressure of the vinevis reduced by 'the two ,regulators 19 .and 29 .andfiiows through the .conduit .2| to the .fittings il.; 'The medium enters the bushing member 5B,

isiiltrere'd or .strained by the strainer 'Bl 'and :enters the opening 159) lea-ding to the chamber 131. The medium is 'effective to unseat the valve disc `v6l zand to vdrive the .piston downwardly past the aperture '41 whereby rthe medium flows :to the vorifice and :is introduced into the tank. The medium is 'effective to dilute or displace the fuel vapors which may be formed in the space above y.

the fuel. l

The ilapper Ll2 is prevented from closing. the venting passage 26 by therplunger, which, Yas shown in broken lines in Fig-ure 5-zis now extended from the body 25 and engages the extension 32 of the dapper and maintains the napper away from the venting opening, thereby permitting free .passage of the fuel vapors to the conduit v9.

When it is desired to restore the system to its normal condition, the source (of the purging medium is disconnected and `t-he conduit 2| is vented to 4the atmosphere. rllhis permits the .spring 69 to yreseat the valve disc 'of the piston and retract the plunger. Thereafter, if the pilot lands a't ahigh speed and stops abruptly, a surge of .fuel is again adapted to cause the flapper to close the venting passage.

While the present invention has been described in connection with an aircraft fuel tank purging or vapor diluting .system by Way of example, it will be understood that the principles involved can be applied to systems for other craft or vehicles 'where itis vdesired to 'purge or :dilute fuel vapors. For example,V the fuel tanks :of .speed 6 boats, armed motor vehicles .and tanks ymay be protected with apparatus substantially .inaccord- .ance with the .invention From the foregoing description it will be seen that the present invention .provides :improved .fuel vapor diluting and purging apparatus. "The appara-tusis readily operated, and once put into operation, functions automatically. 'The danger of bursting the tanks is eliminated. The fitting serves .as a'apper valve, `a apper valve operating means, a check valve, and fa purging medium introducing means. lThe parts thereof are rugged .in construction and Acan readily withstand any 'rough usage :to which they may be subjected.

various changes may be `made .in the form, construction andarrangement of the parts herein, without departing from the spiritzand scope of the invention and without vsacrificing any of its advantageait is to be understood `that all matter herein is to be interpreted as illustrative and not in any limiting sense.

VIt is also to be understood that the following claims are intended to Icover all the vgener-ic and .specific vfeatures of the invention herein Idescribed, 'and all statements of the scope of the invention which, as a, matter of language, .might be said to fall therebetween.

I claim:-

1. `In .an apparatus of the class described, Ithe combination of a fuel tank .having a venting passage, valve means for closing said passage in response to inertia or in response to the surge of fuel in said tank towards .said passage'. a source of inert mediumunder pressure, .means .for intro- 'ducing the medium into said tank, and :means associated `with .said last :means -and operablel vby themedium for preventing .said valve meansffrom closing said passage.

y 2. .Inl an apparatus yof vthe class described, the

.combinationlof a fuel tank having a venting passage, yalvemeansfor closing said passage in re#- rsponse to inertia or in Vrcsponselto the surger of fuel in said tank towards said passage, ayzsource of ,inert :medium underpressure, means for'releasing 'the medium from its source, .means for -intro-- ducing the medium linto said tank, and :means associated with said .last means .and operable 'by the medium for `preventing 4said valve means :from closing said passage.

43. 'In lan apparatus of the class described, th combinanon :of a fuel tank having a venting passage., valve means :for closing said passage in response to inertia or in response to the surge Io'f'fuel.1in-said tank towards said passage., a source lof inert medium under pressure, means `for `introducing lthe medium into said tank including pressureregulating means, `and'mea'ns associa-ted with said introducing means and operable by `the medium for Ipreventing 'said valve means .from closfing said passage. K

4. In an apparatus of the Aclass described, the :combination of .a fuel tank having a venting pas'- sage, valve means in said :tank adjacent said pas .sage for closing said passage 'n Aresponse to infertia Ior .in response to the surge of fuelnln said tank 'towards said passage, a container ,of inert medium under pressure, means forreleasing the medium from said container, means for introducing the inedilnn 'into said ta'nk including a. twosta-ge pressure regulator, and means operable by the medium .introduced into said `tank for preventing said valve means from closing said passage.

;5. A .fitting for .fuel tanks comprising a having la venting passage therein, -inertia responsivevalve means for closing said passage, said body having asecon'd-passage for introducing a medium under pressure into a Vfuel tank, and means adapted to be operated by the pressure medium owing through said second passage for Avpositioning said valve` means to maintain said passage open.

6.' A tting for fuel tanks comprising a body havingY a venting passage therein, a pivotally mounted inertia responsive valve `member for closing said passage, and means adapted to be operated by a pressure medium for positioning said valve memberto maintain said passage open.

7. Aiitting for fuel tanks comprising a body having a venting passage therein, an inertia responsive pivotally mounted valve member for` closing said passage, and a plunger adapted to bev operated by la pressure medium vfor positioning said'valvememberto maintain said passage open.

8. A fitting for fuel tankscomprising a body havingfa venting passage therein, a pivotally mounted". inertia responsive valve member adja- `eentsaid'passag'e for closing said passage, Vsaid valve? member having an extension thereon and acounterbalancing arm, means including a passage for conducting Sa medium under pressure through the fitting, a piston adapted to be operated -by the medium, and a plunger on said piston adapted to'engage said extension' and position said valve member to maintain said venting passageopen;` i 9. A fitting for'fuel tanks comprising a body means having aventing passage therein, valve -means for closing .said passage, said body means having .a chamber provided with a pressure me- .diurninlet and a pressure medium outlet, a, piston f Y in'said'chamber having a valve member for clos- Y ing saidlinletto shut oi communication between said inlet and said outlet, and a plunger 'carried by said pistonV adapted to engage said valve means .and prevent said valve means from closing said vventing'passage.

Y 10. iivttingcforv fuel tanks comprising body means-having a venting passage therein, valve means for closing said passage, said body means having a chamber provided with a pressure medium` inletA and a pressure medium outlet and a passage leading from said outlet and terminating in a metering orifice, a piston in said chamber'having a valve member for closing vsaid inlet Y f 'to shut off communication between said inlet and said;outlet, resilient means for normally urging said vpiston towards said inlet, and a plunger car- .ried by said piston adapted to extend out of said vbody means and engage said va-lve means and prei vent -said valve means from closing said venting passage. Y Y Y V11.A fitting for fuel tanks comprising 'a body having a venting passage therein, a flapper valve memberadjacent f said passage for closing said Y passage,V said valve member having an extension thereonand a counterbalancing arm, a piston adapted to be operated by a pressure medium, and

z8 and a plunger carried by said 'piston adapted to engage said valve means and prevent said valve means from closing said venting passage.

13. A fitting for fuel tanks vcomprising-body means having a venting passage therein, inertia yoperated valve means for closing said passage,

said body means having a chamber provided with pressure medium inlet and a pressure medium outlet and a passage leadinghfrom said outlet and terminating in a metering orifice, a piston in said chamber having a valve member for closing said inletto shut off communication between said inlet and said outlet, resilient means for normally 'urging said piston towards said inlet, anda plunger carried by said piston adapted to extend out of said body and engage said valve means and prevent said valve means from closing said venting passage. s l 14. In a system of the class described,-the combination of a fuel tank having a venting passage, a pivotally mounted valve member for closing said passage inres'ponse to inertia `or in response .to the surge of fuel in said tank towards saidy passage, a source of inert'medium under pressure, means for introducing tne medium into said tank, and means associated with said last means ladapted to be operated by the medium for preventing said valve member from closing said passage. i 15. In a system of the class described, the combination of a fuel tank having aventing passage, Y

a pivotally vmounted valve member. for closing said passage in responsev to inertia or in response to the surge of fuel in said tank towards said Y adapted to be operatedbythe `medium for pre:-

venting said valve! member from closing, said passage' i .1. .Y

16. In a system'of the class described vthe combination of a fuel tank having a venting passage closing said passage inresponse to inertia or in therein, a pivotally mounted inertia responsivey valve member adjacent said passage for closing said passage in response to' inertiagor in response to the surge of fuel in said tank towards said passage, said valve member having an' extension thereon and a counterbalancing arm, a source of inert medium under pressure,.means for introducing the medium into said tank, 'a piston associated with said last means adapted to be operated by the medium, and a plunger 'on` said piston adapted to engage said extension and position said valve member to maintain said venting passage open; Y

V17. The combination of afuel tank and a tting attached to said tank comprising a body having a venting passage therein, valve lmeans. for

yclosing said passage in response to inertia or in response to the surge of fuel in said tank towards said' passage, said body having a chamberfprovided with a pressure medium inlet and a' pressure medium outlet for introducing the pressure medium into said tank, a piston in said chamber having a valve member for closing said inlet to shut off communication between said inlet and said outlet, 'and a plunger carried by said piston adapted to'engage said valve means and prevent said valve means from closing said venting passage.

18. The combination of a fuel 'tank and a tting attached to said tank comprising a body having a venting passage therein, valve means for response to the surge of fuel insaid tank towards said passage, said body'havinga chamber provided with a pressure medium inlet and a pressure medium outlet and a, passage leading from said outlet and terminating in a, metering orice, a piston in said chamber having a valve member for closing said inlet to shut o communication between said inlet and said outlet, resilient means for normally urging said piston towards said inlet, and a plunger carried by said piston adapted to extend out of said body and engage said valve means and prevent said valve means from closing said venting passage.

19. In an apparatus of the class described, the combination of a -fuel tank having a venting passage, valve means for closing said passage, a source of inert medium under pressure, means for introducing the medium into said tank, and means 'associated with said last means and operable by the medium to maintain said valve means from closing said passage while the medium is being introduced into said tank.

20. In an apparatus of the class described, the

' combination of a fuel tank having a venting passage, valve means for closing said passage, a source of inert medium under pressure, means for introducing the medium into said tank including a 'metering orice, and means associated with said last means and operable by the medium to maintain said valve means from closing said passage While the medium is being introduced into said tank.

21. In a system for purging fuel supply means, the combination of liquid fuel storage means normally conditioned for venting vapors of the fuel contained in said means, fuel operated means effective for sealing said storage means to retain the fuel in said storage means, external fluid pressure operated means associated with said fuel operated means for rendering they latter ineffective for sealing said storage means, and means connecting said external means With the interior of the tank to permit purging of said storage means by the medium for operating said :duid pressure operated means.

HENRY ERNEST I-IEIGIS. 

